Avalanche Forecast

Archived

Dec 23rd, 2023–Dec 24th, 2023

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Alpine

Natural avalanches unlikely, human triggered possible.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Kananaskis, Bow Valley, Highwood Pass, North 40, Spray - KLakes.

Up to 20cm of snow fell last night in a short, but intense upslope storm. This new snow and the deeper rain crust have combined to make travel easier and ski quality better. 'bout time!

Confidence

Moderate

Avalanche Summary

We were a bit surprised to see a fairly widespread natural cycle this morning. Lots of sluffs and loose dry avalanches, but the real story is the storm/wind slabs that are out there. There were numerous sz2 to 2.5 slabs noted today. All were below large cliffs, had wide propagations and enough mass to travel far.

Snowpack Summary

We ended up getting 15-20cm late last night/early this morning. It came in with very little wind and so far that remains the case. There is a Dec 23rd interface, but we are still unsure of the quality of this bond. Today at Murray Moraines it was well bonded, except for below large cliffs. See avalanche summary. The Dec crust is getting deeper bit by bit. At the moment it is down 30-40cm and a whopping 15-20cm thick. Interestingly, this crust is what's allowing our snowpack to not be complete chaos. It is extremely solid and supportive up to at least 2350m. Eventually it will break down and leave us hanging, but for now its gluing everything together.

Weather Summary

Looks like a nice, cold day is in store for tomorrow. Mostly clear skies, light SW winds, morning low of -20 and a daytime high of -10.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Wind slabs are most reactive during their formation.
Approach lee and cross-loaded slopes with caution.
Avoid rock outcroppings, convexities, and anywhere the snowpack is thin and/or variable.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.